1. Hierarchical Routing
Definition
Hierarchical routing divides the network into regions or levels, allowing routing to be managed more efficiently in large-scale networks.
- Each router knows full details of its own region.
- It maintains only summary info about other regions.
Key Concepts
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Two types of routing:
- Intra-region routing (within the same region)
- Inter-region routing (between different regions)
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Reduces the size of routing tables and simplifies route management.
Advantages
- Scalable for large networks like the Internet.
- Faster routing table updates and reduced complexity.
- Examples:
- OSPF within an AS (Autonomous System)
- BGP between ASes
2. Broadcast Routing
Definition
Broadcast routing is used to send data packets to all nodes in a network.
Techniques
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Flooding: Packet is sent to all neighbors; can cause congestion.
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Controlled Flooding: Uses techniques like sequence numbers to prevent loops.
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Spanning Tree: Builds a loop-free path ensuring each node gets the packet once.
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Reverse Path Forwarding (RPF): Forwards packets only on the shortest path from the source.
Use Cases
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ARP requests
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Routing updates (e.g., RIP)
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Network discovery
Drawbacks
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High bandwidth consumption.
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Can lead to broadcast storms if not controlled properly.
3. Multicast Routing
Definition
Multicast routing is used to send packets to a group of interested receivers, not to everyone.
Key Concepts
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Uses multicast IP addresses (e.g., 224.0.0.0/4).
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Efficient: single transmission serves multiple hosts.
Multicast Trees
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Source-based Tree: One tree per sender.
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Shared Tree (Core-Based): One common tree for all senders through a central router.
Protocols
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IGMP: Hosts use it to join/leave multicast groups.
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PIM:
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Dense Mode (PIM-DM): Flood and prune model.
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Sparse Mode (PIM-SM): Builds paths only where needed.
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Applications
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Live video streaming
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Online gaming
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Real-time financial updates
Advantages
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Efficient bandwidth use.
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Reduces server load.
Disadvantages
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Complex setup and maintenance.
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Requires multicast-aware network infrastructure.
Let me know if you want a diagram or comparison table for these!